The Dashboard Service shipped along with the Dashboard Server will not work for SDK platform due to some security constraints. So you cannot access the Server’s Dashboard Service outside of the Server.

Also while giving dashboard path, you should not give it as relative path. You need to give the path of the dashboard as absolute path because you are using a service outside of the application. So giving an URL as relative path will not work here. Please refer to the below links to know how to give dashboard path.